A confidential report into the murders of Ben Smart and Olivia Hope has emerged with the startling claim the infamous “mystery ketch” has been identified, with those on board, and the infamous crime had nothing to do with Scott Watson, now serving 19 years inside for the double-killing.

It’s not very confidential now.

The report is the latest public investigative effort into a disappearance. It was written based on research by commercial pilot, engineer and sailor Warwick Jenness with help from yachtie Mike Kalaugher and Keith Hunter, who wrote Trial By Trickery about the case.

The group’s report was leaked to theHerald– the authors have not sought to make its findings public.

It claims to have identified the ketch first thought by police to be linked to the Hope/Smart disappearance, based on the description by a water taxi operator who dropped them off early on January 1, 1998.

The report includes a distant and grainy snap of a woman the authors say is Hope, 17, taken at Marys Bay five days after she and Smart, 21, were said to have been killed following a 1997 New Year’s Eve party.

But Wishart disagrees.

The emergence of the report by the self-styled Maritime Research Group comes ahead of the publication tomorrow of a new book by author and investigative journalist Ian Wishart, which also claims to have identified the ketch, initially the focus of police inquiries.

Last night, Wishart said he knew of the Maritime Research Group report. But he said his book, Elementary, “reaches a different conclusion”.

Presumably they can’t both be right. And there seems to be a third opinion – the police.

A police spokesperson confirmed last night it was “aware of this group and their theories regarding the case”.

“There is nothing in their correspondence that convinces police that anyone other than Scott Watson was responsible for the deaths of Ben Smart and Olivia Hope.”

So I expect the debate will continue.

The report paints the ketch as having a central role in the smuggling of cocaine. At least one of those named in the report and linked to the ketch is serving a lengthy prison term in the Oceania region after being caught at sea with a lot of cocaine.

The report again pits police against the yachting community.

“Any yachtie who looks at the practical side of what happened quickly comes to the conclusion this case presented by the police could never have happened … it’s full of holes,” said Mr Jenness.

Wishart’s book tomorrow may bust the case open. Or it may be disputed, like this report.

Publisher Ian Wishart says a new book will finally solve the infamous Marlborough Sounds murder case.

Wishart will next week publish the book, Elementary — The Explosive File on Scott Watson and the Disappearance of Ben and Olivia.

Wishart said he was “pitching” the book as “solving the case”.

“Finally we know the truth, solving an 18-year-long mystery,” he told the Herald on Sunday.

He also distributed a press release stating: “A new book on the controversial Scott Watson case will be released on Friday, with never-before published information on the killings and what happened to Ben and Olivia.

“A news conference will be scheduled for Friday morning, and details will be provided this week.

“No further information is being released at this point, beyond what is contained in a video trailer that went live this afternoon.”